Due to features such as high flexibility and great convenience of a mobile network and reasons such as that the price is increasingly suitable for the mass consumption market, the mobile network is developed at a high speed, the number of subscribers of the existing mobile network has already exceeded the number of the subscribers of a fixed network, and comparatively universal network coverage has already been obtained.
Since the mobile network has developed at the stage of LTE/LTE+, and possesses broadband features and increasingly wide deployment, it will become increasingly popular to use LTE for a broadband access method. As the introduction of LTE, the shared bandwidth for uplink and downlink in LTE has already reached at 50 Mbps and 100 Mbps, respectively. While the LTE+ bandwidth can reach at 500 Mbps. Therefore, a mobile network has already been capable of supporting broadband access like that of a fixed access network. In other words, after the mobile network is developed to the LTE stage, broadband access demands of subscribers can be satisfied, and especially after introducing a Home eNB (Node B)(HeNB)/femtocell (which is a super-miniature mobile base station put forward in recent years according to 3G development and mobile broadbandization trends) and a small cell. That is to say, LTE can satisfy universal access of broadband, including access at Ethernet rate similar to enterprise internal networks, i.e., 10M, 100M and even higher-rate access can be satisfied.
At the modern times that the mobile network and the broadband network are developed at high speed, another concept, i.e., cloud computing, becomes increasingly hot with the wide development and use of services, i.e., Infrastructure as a Service (IaaS), Software as a Service (SaaS) and Platform as a Service (PaaS), and the application thereof also becomes increasingly popular. With the deepening of IaaS application development, a new service-Network as a Service (NaaS), i.e., network service can be further developed and is called as a tenant network service in the present document. NaaS refers to providing network functions such as network access, switching and routing for clients through the networks of operators, so as to provide the subscribers with the networks similar to physical networks established by enterprise clients. This has the advantage that the subscribers can focus on their own services without distracting on non-main services such as network construction and maintenance. In addition, by managing and supporting the by the operators, higher network security can be obtained, use on demand can be realized and better cost performance can be achieved.
Due to the previously described universal access features of the mobile network, thereby, the mobile network technology can also be used for implementing NaaS. By introducing NaaS related function entities into the mobile network, the NaaS function can be implemented, so that the NaaS service development becomes more popular and more subscribers can be covered. Further, by implementing NaaS in the mobile network, more service income can be brought to mobile network operators, so that network resources can be more widely used and the resource utilization ratio is higher. Besides, virtualization of the mobile network can be implemented by supporting different tenant networks/virtual networks of different clients.
However, the traditional mobile network mainly provides the services supporting single subscriber, such as a telephone service and an INTERNET access service.
FIG. 1 is a network structure diagram of the typical 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)/System Architecture Evolution (SAE), wherein UE is a user terminal equipment, an evolved Node B (eNB) is a base station equipment, an Serving Gateway (S-GW) is a gateway for serving and a Packet Data Network Gateway (P-GW or PDN-GW) configured to connect with an external Internet Protocol (IP) network. A Mobility Management Entity (MME) is responsible for a management function, and a policy and charging rules function is used for implementing policy and charging control. The P-GW allocates an IP address for a subscriber, and related default bearers and dedicated bearers need to be established between the UE and the P-GW through the eNB and the S-GW to implement connections of related services.
FIG. 2 is a flowchart of a typical registration, IP address allocation and service usage of an LTE/SAE network, which comprises the following steps:
In Step 201, it is to perform a random access process. When a subscriber registers to a network, a Radio Resource Control (RRC) connection needs to be established between a terminal and the network through this process.
In Step 202, the terminal transmits a registration request including an identity thereof to MME. The identity may be an International Mobile Subscriber Identity (IMSI) and also an effective S-Temporary Mobile Subscriber Identity (S-TMSI).
In Step 203, it is to perform an Authentication and Key Agreement process (AKA). When the MME extracts the subscriber identity, the MME starts the AKA process to implement mutual authentication between the network and the terminal.
In Step 204, it is to perform a location update and subscriber data insert (and confirmation) process between the MME and a Home Subscriber Server (HSS).
In Step 205, the MME transmits a bearer establishment request to a P-GW.
In Step 206, the P-GW performs subscriber IP address allocation, etc. and returns a creation bearer response. In this message, an IP address allocated to the subscriber is returned.
In Step 207, the MME transmits an initial context request message to an eNB, wherein the initial context request message includes a registration acceptance (also called as connection acceptance) message transmitted to the UE and the registration acceptance message carries information, such as the IP address, etc.
In Step 208, the eNB transmits an RRC connection reconfiguration message to the UE, wherein the RRC connection reconfiguration message carries the registration acceptance message transmitted to the UE and the registration acceptance message carries information such as the IP address.
In Step 209, after RRC connection reconfiguration is completed, the UE transmits an RRC connection reconfiguration response message to the eNB.
In Step 210, the eNB transmits a registration completion (also called as connection completion) message to the MME.
In Step 211, after the UE obtains the IP address, it is to perform related service processes (such as WWW browsing and IMS application) through the established default/dedicated bearers.
Although services such as group telephone/small number dialing are supported in the existing mobile network and IP Virtual Private Network (VPN) services on the mobile network are supported, the implementation of these services has a longer distance from the implementation of the NaaS service. Specifically, the existing mobile network technology cannot implement the NaaS service.
Supports provided by the mobile network to enterprise networks are comparatively few. For example, the implementation of a Virtual Private Dial-up Network (VPDN) based on Layer 2 Tunneling Protocol (L2TP), an UE based IPsec VPN technology or the like cannot support the implementation of a plurality of enterprise networks in the mobile network, isolation between the different enterprise networks, and, the isolation between the enterprise network the mobile network itself, etc. In addition, even though related VPN functions are implemented, i.e., the access of virtual networks is implemented in the existing mobile network implementation mechanism, service switching on the PDN-GW is needed, and Under the situation that the UE implements enterprise network access by a same eNB, if traffic of the enterprise networks is switched via the P-GW, the bandwidth of backhaul networks is greatly wasted, unnecessary traffic pressure is caused to related Gateways (GW) and thus it is not reasonable. Therefore, new solutions are needed.